you can say "祝你順利通過考試" and yes "那次考试非常难" is correct

祝你驾驶考试顺利通过！ Yes, you are right. 那次考试非常难。

In my view, you had better translate the first sentence into chinese:祝你驾照考试顺利或祝你驾照考试好运。现实生活中很少说驾驶考试，虽然实际上确实就是驾驶或者开车。 The second is ok.

怎么说：Good luck on your driving test。 可不可以说：祝你好运考开车的试。 “考试 ”the two word not get together, only used for “你考了什么试？” same as"你刚刚有什么考试？" The first just for colloquial language,it was right but inappropriate. my eng was poor ,wish you can understand it.

“祝你好运”和具体的事情结合（对应于英语的 on sth.）可以用以下格式：祝你...好运/顺利。例如：祝你驾驶测试好运/顺利。祝你这次旅行好运/顺利。